1. Field of the Invention
The present invention relates to a method for the start-up of a numerical control of machine tools or production machinery, wherein the numerical control includes a main computer and at least one follow-up device, which are connected with each other via a data transmission network, wherein the at least one follow-up device can be addressed by the main computer via a logical address, to which a hardware address with information regarding the physical address of the at least one follow-up device is allocated through the data transmission network.
The present invention furthermore relates to a numerical control for machine tools or production machinery.
2. Discussion of Related Art
At present, numerical controls (NC) are primarily utilized for the control of machine tools or production machinery. In order to design such numerical controls as flexibly as possible, they are often modularly constructed. In the course of this, several follow-up devices, such as control units, inverter modules, or also programmable logic controls (PLCs), for example, are connected to a main computer.
The main computer makes the user interfaces required for operating the numerical control available, such as keyboards and monitors, and is used for the preparation, storage and processing of programs. Closed-loop controls, for example, are contained in the control units and are used for controlling inverter modules, which in turn control motors. The control units furthermore include digital and/or analog interfaces for recording actual values, which are continuously required for controlling the control unit during a program run. The actual values to be recorded can be, for example, positional (location) values, velocity values, acceleration values, or also electrical current values. PLCs are used for triggering switching processes as a function of circuit conditions, for example limit stop switches. The follow-up devices are controlled by micro-processors, the same as the main computer. The main computer and the follow-up devices are connected by a data transmission network for transmitting data.
The modular construction has the advantage that, depending on how many and which follow-up devices are connected to a main computer of a numerical control, the most diverse requirements can be met. For example, it is possible by the same main computer to control different machine tools (triple-shaft and quintuple-shaft milling machines), production installations with different numbers of drive systems, or also production robots having a different number of servo-controlled joints, by varying the follow-up devices. Moreover, modular numerical controls can be easily expanded later.
So that the main computer can address the follow-up devices independently of each other, they have individual hardware addresses allocated to them. Furthermore, in order to know which follow-up device has what function, it is necessary to allocate a hardware address to each logical address in the main computer. Only then is it possible for the main computer to determine, for example, which control unit, or which inverter module, must be addressed for displacing a defined feed shaft of a machine tool to be controlled.
Up to now, the allocation of the logical address to the hardware address had to be performed manually, for example by a manual entry of the hardware addresses in the main computer by a technician during the start-up of the machine tool or production machinery. A further possibility exists in entering their logical address directly into the follow-up devices. This can take place, for example, by setting a code switch, or by entering a specific code word into a memory in the follow-up device, which in turn can be read out via the data interface of the follow-up device. However, both methods are quite elaborate and prone to errors, particularly in connection with voluminous machinery containing a large number of follow-up devices.